Electronic spectroscopy

17 Jul 2012

Colored Note Cards as a Quick and Cheap Substitute for Clickers

Submitted by Chris Bradley, Mount St. Mary's University
Evaluation Methods: 

Use of the cards gives a rough "eyeball" evaluation of student learning throughout a lecture. Using the cards, for me at least, also provides a gauge of attendance as well and also if it waxes or wanes during the class period.

Description: 

For many years I have resisted using clickers, mainly because at our university there is no standard universal clicker. I wanted to keep student costs as low as possible but also desired the type of live feedback during a lecture that clicker questions can provide. In both my general chem. (200-300 students) and upper division courses (50-75 students), I now pass out 4 or 5 colored notecards on the first day of class and make sure everyone has one of each color. I then do clicker style questions and color code the different answer choices in powerpoint and ask them to hold up their choice after 15-60 seconds depending on the question. This has worked well to provide me instant feedback on difficult topics and doesn't end up singling out any particular student, which most students detest in larger lecture courses.   

 

Learning Goals: 

Students are able to provide feedback to the instructor on questions quickly and "anonymously" and allow one to adjust the direction of a lecture on the fly.   

Prerequisites: 
Corequisites: 
Equipment needs: 

NA

Implementation Notes: 

I typically use between 4-6 clicker questions during a 50 minute lecture. I'm sure someone could use more/less based on an individual's needs. I think the key is to use clicker style questions from the beginning of the class on a daily basis to remind students to bring the note cards in a book/binder/bag. This is really the only problem I have encountered- students often forget their cards. It is probably a wash though, as I'm sure students can also forget clickers.  

Time Required: 
1-5 minutes (depending on the problem)
15 Jun 2012

NMR Coin-Flip Game

Submitted by Adam Azman, Butler University
Description: 

A simple coin-flipping game to help students understand the origin of spin/spin splitting in 1H NMR.

  • A quarter is taken as 'set of equivalent protons' with a 'chemical shift' value of $0.25.
  • One penny is flipped 2000 times.
    • If the penny lands heads, $0.01 is added to the value of the quarter; value = $0.26
    • If the penny lands tails, $0.01 is subtracted from the value of the quarter; value = $0.24
    • Keep a running tally of the occurance of each outcome
  • By flipping one penny 2000 times, students will see a 1000:1000 ratio of the two outcomes ($0.24, $0.26). This mimics the origin of a doublet from one neighboring proton with j-value $0.02
  • Students can 'flip' up to 9 pennies to simulate up to 9 neighboring protons all with j-value $0.02
  • Students can also 'flip' up to 4 nickels to simulate additional neighbors with a second j-value of $0.10
  • After 5 trials, a link appears to an explanation page tying together the concepts of flipping coins and NMR splitting/j-value

It's actually pretty hard to distil into a set of simple, easy-to-understand, easy-to-follow rules. The intervention would be better suited for actually physically bringing pennies into class and run the demonstration physically with students (which I plan to do). The web resource can be used in class to simulate the statistical mixture (especially if the class contains too few students to practically achieve a statistical distribution manually). The web resource can also be provided to students after they leave the class to reinforce the concept.

NMR Coin-Flip Game Preview Image

Prerequisites: 
Corequisites: 
Learning Goals: 

A student should be able to explain the origin of NMR splitting, the meaning of a j-value, and predict the splitting pattern of simple systems with up to two different j-values.

23 Jun 2011

Geometry and Magnetism Worksheet_ Bioinorganic

Submitted by Sheila Smith, University of Michigan- Dearborn
Evaluation Methods: 

As an in-class exercise, this activity is evaluated based on the quality of the discussion that is generated. Students work together in groups to apply their knowledge of electronic structure and magnetism to answer the question posed. In a perfect world, this discussion leads to further discussion on techniques that can be used to distinguish between different geometries.

Description: 

This is an in class exercise that I use to introduce structure and magnetism to a junior/senior level course on bioinorganic chemistry. The class is cross-listed between Chemistry and Biochemistry. All of the students have had general chemistry and organic (with some exposure to MO Theory). Many of the students have also had the sophomore-level inorganic course, which delves extensively into MO theory, and some of the the students have also had the senior-level course on transition metal chemistry which looks deeply at d-orbital splitting. Because of the different levels of preparedness, the questions that I discuss in class as a result of the worksheet vary.  

Learning Goals: 

• A student should be able to identify the number of d-electrons for a given oxidation state for a given metal.
• A student should be able to fill the orbital energy diagram, applying the Aufbau Principle, Hund's Rule, and the Pauli Exclusion Principle.
• A student should be able to distinguish between a magnetic and a paramagnetic configuration.

Prerequisites: 
Corequisites: 
Course Level: 
Equipment needs: 

None

Implementation Notes: 

While this LO was written with a bioinorganic course in mind, it could easily be used in an inorganic class as an example of the usefulness of magnetism to applied problems.

Time Required: 
15-20 minutes depending on the amount of discussion you wish to have
25 May 2011

Catalysis using functionalized mesoporous silica

Submitted by Randall Hicks, Wheaton College
Evaluation Methods: 
Unless a student has done some independent research (lab or literature) in this area previously, I expect that none of them will have any experience with this work. Therefore, I assess on the effort that students made to answer the assigned questions and on their contribution to in-class discussion. The instructor of record (for senior seminar) is also present to observe the class proceedings and can decide how to integrate that into an overall grade for the course. 
Evaluation Results: 

Without the review of unfamiliar terms and concepts on the first day of the two-day activity, I doubt that many students would be able to tackle this paper. However, after going through all that, students do a fair job of answering the questions.

The answers to most of the "general questions" can be found from web searching. The students that are motivated to do so have dug up answers for these questions. Question #6 is difficult for them, but serves as a good point to initiate conversation about why larger mesoporous materials are useful. Question #7 is also foreign, but it usually comes up in the first class and so students can piece together a response for it here. 

Answering the "characterization method" questions has proven more difficult for the students, particulalry because most if not all of them lack experience with x-ray diffraction and gas adsorption techniques. They can look up Bragg's Law and calculate a parameter given the other values (solve for x, essentially) even if they don't know exactly what that value represents. A4 is particularly difficult as they need to find the answer in the accompanying paper. Responses to questions on gas adsorption are understandably murkier yet. Again, this is where I can go into more detail on the method in class discussion. On the other hand, questions in C and D on UV-Vis and IR, respectively, are easier for them given their familiarity with those techniques. These questions are usually answered well. D1, on site-isolation, sometimes requires further explanation. And, finally, while students have NMR experience from organic, they're not usually knowledgeable on solid-state NMR. Some of these answers can be found online or in the paper, but this is another are where a short discussion is helpful.

Depending on the length of discussion in a particular class, there is not always time to fully get into the catalysis results. However, the answers to these questions can be found in the main manuscript and are correctly reported.   

Description: 

This paper, while not fundamentally groundbreaking, serves as a nice introduction to the field of mesoporous materials. I like that it covers synthesis, characterization, and an application of the materials. I have used this paper in our senior seminar course as the basis for discussion of this area of chemistry. Discussion questions cover aspects of sol-gel chemistry, powder diffraction, gas adsorption, IR, solid state NMR, UV-Vis, and catalysis.  

Prerequisites: 
Course Level: 
Learning Goals: 

Upon reading this paper, students should be able to:

• Describe at least one method by which mesoporous materials can be both synthesized and functionalized

• Explain how x-ray diffraction, gas adsorption, solid state NMR (and to a lesser extent, IR and UV-Vis) can be used to characterize mesoporous materials

Implementation Notes: 

As part of our seminar, each faculty member rotates through to present a paper for discussion in his or her area of chemistry. The class meets for 1 hr 20 minutes twice a week (Tuesday and Thursday). Students are given the paper on a Tuesday, without much preface, and are asked to briefly read over the work for Thursday. In class on that Thursday, I have them to present an overview of the paper and submit any terms with which they are unfamiliar. I spend the majority of that day giving an introduction to the field, defining unfamilair terms, and answering questions. Then I distribute a handout with specific questions for the students to answer. Some questions are to be done by all, others are assigned in groups. While the groups are evenly populated, I often assign a different number of question to each group. For instance, because students have been introduced to IR, NMR, and UV-Vis, I have one group tackle all three of these sections on the assignment. For topics with which they're not likely familiat (XRD, gas adsorption), I assign one of these per group. They have until the following Tuesday to work on the questions. At that point, I ask students to present their answers, and we resume the class discussion. (I have attached the handout that I give to students, and a version with my answers, below.) 

Related note: Although we are moving to a two-course inorganic sequence in AY 2012-13, I do not have the ability to "squeeze" materials chemistry into my (currently) one semester course; I therefore relish the opportunity to present this paper in our seminar course. If you have the time to cover materials in your normal inorganic sequence, you may be able to present this paper in one class instead of two. 

If you have faculty privileges on VIPEr, then solutions to the questions can be found in the linked learning object (see related activities).

Time Required: 
Two (2) 80-min classes
3 May 2011

Teaching Tanabe-Sugano Diagrams

Submitted by Sheila Smith, University of Michigan- Dearborn
Evaluation Methods: 

As an in-class exercise, this activity is evaluated based on the quality of the discussion that is generated. Students work together in groups to apply their knowledge of electronic structure and graphs to answer the questions posed. It can be easily modified to serve as an exam -question for more direct assessment. For an exam, I may skip the first question, providing students with a single T-S diagram, and asking questions about a complex based on that T-S diagram.

Evaluation Results: 

Usually ,this particular example spurs some debate about whether the [Mn(H2O)6]3+ complex is in fact high-spin (because of the 3+ oxidation state. This in itself is a valuable review since it requires student reasoning of the effects on spin of metal identity, oxidation state and ligand field strength.

Description: 

For years, I spent 2-3 days a semester working through Tanabe-Sugano diagrams, their development from terms, their evolution from Orgel diagrams, their analysis to give transition energies (the old ruler- trial and error analysis) and nephalauxetic parameters.  Recently, colleagues in VIPEr convinced me that my time in class could be better spent, but I am not willing to completely give up on Tanabe-Sugano.  For that reason, I have developed this exercise that boils the application of T-S diagrams down to an exercise in interpreting graphs (a skill which is sadly lacking in some of my students). It omits some of the analysis of the T-S diagram, but I think it gives adequate coverage to what is truly the most useful information to be gleaned from T-S diagrmams.

Learning Goals: 

A student should be able to identify the appropriate T-S diagram to use for a particular metal complex. A student should be able to predict whether a complex will be high-spin or low-spin and relate this to a particular position on the T-S diagram (x-axis). A student should understand that electronic transitions will not affect the value of either DelO or B, therefore any transition should be represented by a vertical line. A student should be able to predict the spin allowed transitions for a transition metal complex based on the appropriate T-S diagram. Given the necessary information to determine an exact x value (DelO/B), a student should be able to predict the energy of a particular electronic transition. A student should be able to convert n energy in wavenumbers to a wavelength in nm.

Prerequisites: 
Equipment needs: 

It may be helpful to provide students with rulers / straight edges. Students will need calculators.

Course Level: 
Implementation Notes: 

It is helpful to have available for students a complete set of T-S diagrams, either from your textbook or photocopied.

Time Required: 
25-30 minutes as In-class exercise
2 Feb 2011
Evaluation Methods: 

There are a series of questions at the end of the lab that students must address in a full written paper. I have students write a paper in JACS format (the other labs taught in the semester, students write communications in JACS format).

Evaluation Results: 

Overall, student's reports have been good in this area. The course is a writing intensive course. What I've found is that the students perform better when writing their reports as they go through the weeks (as opposed to those students who wait until the last minute and generally forget what they've done). I have not tried this, but I will most likely have students write sections of the paper each week so they get more feedback from me in the process.

Description: 

This is a lab experiment designed to cover an array of techniques, including metal complex synthesis, spectroscopy and electrochemistry.  Overall, the goal is to synthesize the metal complex Ru(bpy)32+, exchange the counter ion to demonstrate changes in solubility, absorbance and emission properties (including excited state quenching through energy and electron transfer, and ground state oxidation), as well as cyclic voltammetry of the complex.  It is a three week lab: Week 1 - Synthesis of the complex; Week 2 - Electronic spectroscopy of the complex; Week 3 - Electrochemistry of the complex.

Corequisites: 
Course Level: 
Learning Goals: 

After this laboratory experiment is complete a student should be able to explain "What are the possible processes that can occur when a molecule absorbs light?" In addition, they should be able to explain the many ways in which electron transfer can occur and different methods of studying electron transfer.

Equipment needs: 

Chemicals: Ruthenium trichloride; 2,2'-bipyridine; NaOH pellets; 31% phosphinic acid; KCl; acetone; ammonium hexafluorophosphate; ether; hydroquinone; quinone; ammonium cerium(IV) nitrate; acetonitrile; tetrabutylammonium hexafluorophosphate; ferrocene Supplies/Equipment: round bottom flask; reflux condenser; hose adapter; stir bar; hot plate; filter; beaker; nitrogen or argon line; IR spectrophotometer; UV/Visible spectrophotometer; Fluorimeter; disposable fluorimeter cells; 5 mL volumetric flasks; potentiostat

Related activities: 
Implementation Notes: 

I have done this laboratory experiment twice. The experiment can be mixed and matched depending upon what you want to do!

Time Required: 
3 weeks - 4 hours labs. The electrochemistry week does not require the whole time.
3 Sep 2010

First Isolation of the AsP3 Molecule

Submitted by Anne Bentley, Lewis & Clark College
Evaluation Methods: 

The students’ written answers to the questions and presentations of the questions were graded.

Evaluation Results: 

Because we discussed this article at the end of the semester, the stretching mode analysis was not fresh in the students’ minds.  They appreciated the chance to review earlier portions of the course. 

Description: 

Early in 2009, Christopher Cummins’ group at MIT reported (in Science) the synthesis of AsP3, a compound that had never been isolated at room temperature.  Later that year, a full article was published in JACS comparing the properties and reactivity of AsP3 to those of its molecular cousins, P4 and As4.  The longer article is full of possibilities for discussion in inorganic chemistry courses, with topics including periodic trends, NMR, vibrational spectroscopy, electrochemistry, molecular orbital theory, and coordination chemistry.

Corequisites: 
Prerequisites: 
Learning Goals: 

After reading and discussing this paper, a student should be able to:

•    recognize the general names used for groups 15, 16, and 17
•    derive the expected number of Raman resonances for the AsP3 and P4 molecules
•    outline the trend observed in P–P vs As–P bond strength
•    compare the reactivity of P4 and AsP3 in at least one example and make predictions regarding As2P2 and As3P reactivity

Subdiscipline: 
Implementation Notes: 

This learning object was developed as one of five journal article discussions included in a small (5 student) senior-level inorganic course in the spring of 2010.  This course is the only inorganic course (aside from a separate inorganic laboratory) offered in our curriculum.

The literature discussions were interspersed throughout the semester.  This journal discussion was the final one in the semester, and we discussed questions 1-4 as a group before each individual presented the results of the reactivity studies they had chosen (question 5).  Student presentations were informal; it was a good opportunity for them to learn how to condense information.   

Time Required: 
30 minutes as implemented. A larger class might take more time.
23 Aug 2010

Using Solid State Chemistry and Crystal Field Theory to Design a New Blue Solid

Submitted by Barbara Reisner, James Madison University
Evaluation Methods: 

When the literature discussion was used at Reed in Spring 2011, the discussion questions were collected and graded on a 10 point scale, 1 point for each question with the exception of #5, worth 2 points, plus an additional point for effort.

Evaluation Results: 

Of the 17 students that turned in discussion questions, 2 students (12%) earned 9.5 points out of 10, 7 students (41%) earned 8-9 points, 4 students (24%) earned 7-8 points, and 4 students (24%) earned 6-7 points.

On question 1 (ionic radii), most students did not cite the source of their data or did not specify a coordination number for the ions, and fractions of a point were deducted for these omissions.  On question 2 (bond distances), 7 of 17 (41%) students did not calculate predicted bond distances from the ionic radii.  In general, students did very well on questions 3 and 4.  Question 5 proved more of a challenge.  Common errors included no drawings of the d-orbitals in the trigonal prismatic crystal field or unsatisfactory explanations for the crystal field splitting pattern.  Only 5 of 17 students (29%) provided the correct answer of magnetism on question 6.  Other answers were incomplete or did not explain how the experiment would verify the presence of high-spin Mn3+.  On question 7, nearly all students successfully converted the energy scale to photon wavelengths, but 4 students mislabeled the electromagnetic region, as either all infrared or all ultraviolet.  Six of 17 students (35%) answered question 8 correctly.  The most common error was no explicit indication that transitions in the octahedral geometry are symmetry forbidden by the LaPorte selection rule, whereas this rule is relaxed in trigonal bipyramidal coordination.

Description: 

This communication from the Journal of the American Chemical Society (J. Am. Chem. Soc. 2009, 131, 17084-17086.  doi:10.1021/ja9080666) describes the use of classic solid state chemistry to dope Mn3+ in two different host oxide structures to create new blue pigments.  The key to the blue color is the unusual trigonal bipyramidal coordination of the Mn3+ ion in these structures.  Discussion of this paper in class provides an opportunity to discuss solid solution chemistry in extended structures, including both their synthesis and characterization as well as illustrate the application of crystal field theory to understand the color of a transition metal doped oxide.  An extensive list of discussion questions is provided so that the learning activity can be tailored to a variety of different curricular uses and student backgrounds.

Prerequisites: 
Corequisites: 
Learning Goals: 

After reading and discussing this paper, a student will be able to:

  • Describe the basic considerations in the design, synthesis, and characterization of solid solutions in extended structures.
  • Identify and describe the distinguishing features of several different mixed metal oxide structures.
  • Given structural information, apply the principles of crystal field theory to explain the color and electronic spectroscopy of a transition metal ion doped oxide.
Implementation Notes: 

An extensive list of potential discussion questions was developed by Barbara Reisner and Maggie Geselbracht, two faculty trained as solid state chemists so that other faculty would have a range to choose from and use, depending on their curricular goals.  We believe that this is an ideal paper to introduce extended solids into the inorganic curriculum with the “hook” for both faculty and students of an easy connection to coordination chemistry.
 
The first time this learning object was used in the classroom was by Barb at James Madison University in Fall 2009 in a second semester Inorganic Chemistry Course. This paper was not originally used as a literature discussion but instead turned into a lecture. The lecture was used to tie up a unit on solid state chemistry, and the figures in the paper to discuss solid state structures and ionic radii; basic crystallography, powder diffraction, and Vegard’s Law; and crystal field theory.

Maggie used this literature discussion activity as the final conference for her sophomore-level inorganic chemistry course at Reed College in Spring 2011. She selected 8 of the discussion questions from the full list and provided them to her students in advance of the conference meeting. This shortened list is available as an attachment above. Students were asked to read the paper and write out the answers to the discussion questions prior to the discussion. The solutions document to these 8 questions is available to registered faculty users on VIPEr.

 

Time Required: 
50 minutes
17 Jul 2010
Evaluation Methods: 

Upon completion of the experiment the student pairs submit a brief summary of their results and plans to developing a formal report. A draft report is then written in the style and format of an American Chemical Society journal article; the draft must be thoroughly referenced. The instructor reads the draft and returns it to the students with suggestions for revisions. The final version of the report is evaluated in accord with criteria presented in the policy section of the laboratory manual.

 

Evaluation Results: 

Given the integrated nature of this exercise, the laboratory reports indicate whether or not the students have mastered the essential ideas of coordination chemistry. The reports reveal skill in laboratory technique through the percent yield and quality of the products and recording infrared and electronic absorption spectra and in interpretation of the spectra. Although reports are often of high quality and reflect considerable insight, some students seem not to grasp the distinction between molecular and electronic structure. A somewhat larger number have difficulty synthesizing the reaction observations and the measurements, computation, and database results into a comprehensive narrative. That requires further discussion with the instructor. Many students need to learn when to reference statements appropriately.

Description: 

This experiment, intended for an upper-level inorganic chemistry course, involves classical transition-metal coordination compounds. The purpose of the exercise is to compare the physical and chemical properties of coordination complexes containing copper(II) and silver(II) ions bound to the anion of pyridine–2–carboxylic acid, also known as picolinic acid, picH. The metallic elements copper and silver are in the same family in the periodic table, but their chemical properties are quite different. Although Cu(II) is the stable oxidation state in aqueous solution, Ag(II) is powerfully oxidizing in water. The conjugate base of picH, pyridine–2–carboxylate or picolinate ion, acts as a ligand toward these metal ions, binding to them in chelating mode through the pyridine ring nitrogen atom and one of the carboxylate oxygen atoms. The compounds are synthesized in water at room temperature. In both cases picolinic acid is deprotonated to give picolinate ion, which then binds to Cu2+ and Ag2+, yielding products formulated as M(pic)2. For silver, Ag+ must be oxidized to Ag2+. Molecular and electronic structural characterization is accomplished through infrared, electronic absorption, and electron spin resonance spectroscopy and density functional calculation. Available crystal and molecular structure information is surveyed using the Cambridge Structure Database. 

Prerequisites: 
Course Level: 
Subdiscipline: 
Learning Goals: 

• Students will discover that two structurally similar transition metal compounds can be synthesized cleanly from water solutions.

• Students will engage in the molecular and electronic structural characterization of both compounds. They should appreciate the need to employ a variety of physical measurements to develop a comprehensive structural understanding of a molecule.

• Students will develop an appreciation of differences arising from position in the first vs. second vs. third transition series (the gold(II) compound does not exist).

• Students will learn to do an electronic structure calculation on a transition metal compound and to explore a crystallographic database.

Equipment needs: 

• Pyridine-2-carboxylic acid (picolinic acid), copper(II) acetate hydrate, silver(I) nitrate, ammonium peroxodisulfate, sodium carbonate, deionized water

• Beakers, magnetic stirrers, magnetic stirring bars, filtering funnels, filtering, vacuum drying capability, vials

• FTIR spectrometer (mineral-oil/NaCl or KBr disks or KBr and press for pellet making), UV/Visible spectrometer (quartz cell, water), ESR spectrometer (quartz tubes)

• Access to density functional theory computation software (Spartan, for example) and to Cambridge Structure Database

Implementation Notes: 

Students do this experiment in pairs. The synthetic reactions are easily accomplished. The copper reaction gives either the anhydrous material or the monohydrate. The reaction filtrate will yield large crystals, but this requires several weeks at room temperature. The silver compound that does not precipitate from the initial reaction will decompose in solution within a few days at ambient temperature. We store the silver compound in a refrigerator and allow the storage vial to warm to room temperature before removing a sample for physical measurements. The IR measurements are straightforward. We record both solid-state and solution electronic absorption spectra for comparison with the IR spectra (solid state) and to obtain molar absorptivity values. Both compounds give strong ESR spectra for solid-state samples, and a procedure for data analysis is provided. The density functional calculation for the copper compound works well using low-level Spartan software; for silver the number of electrons is too large for successful calculation. Students should understand that generally the simple Spartan DF computation applies to the molecules in the gas phase.

Time Required: 
• One and a half hours for syntheses by a pair of students. • Two-three hours for spectroscopy.
17 Jul 2010

Kinetics of Ligand Substitution Reactions of a Pt(II) Complex

Submitted by Scott Cummings, Dominican University
Evaluation Methods: 
(1) Check students' ability to use correct calculations and techniques to prepare solutions of known concentrations; (2) Review students' fit of first-order and second-order integrated rate equations to a kinetics data set, and discuss with them their choices of which data to use and which to reject; Also check their calculation of the observed rate constant from this fit. (3) Review students' analysis of how changes to the concentration of the excess nucleophilic entering ligand affects the observed rate constant, and how this relationship establishes the best rate law for the reaction. (4) Poll students on what follow-up experiments they might use to test their conclusion or resolve uncertainties. (5) Read lab report (includes this and related experiments involving this coordination compound) to ascertain how students' use data to support a conclusion (proposed mechanism) and address uncertainty and error.
Evaluation Results: 
Not all students who enroll in this advance lab course have completed Introductory Chemistry, so this is the first exposure to experimental kinetics for some. Most of my discussions with students address their confidence in knowing solution concentrations (a reflection of lingering difficulties with lab technique and calculations). Nearly all students can satisfactorily fit first-order and second-order integrated rate equations to data for a single kinetics run, but some struggle to understand the purpose of running trials using varying thiol concentrations and how these results are important for determining the form of the rate law. Inviting students to compile their results with those of previous year’s students and primary research literature raises important issues about reproducibility; some students, though, become disappointed when their results display evidence of poor lab technique. Stronger students recognize, in their lab report, how their results relate to relevant research literature and make connections to other experiments they perform with this coordination compound.
Description: 
This inorganic lab experiment, focusing on the kinetics of ligand-substitution reactions of a square-planar Pt(II) complex, involves collecting UV-vis absorption data and analyzing the results to determine a rate law to support one of three proposed mechanisms.
Prerequisites: 
Subdiscipline: 
Course Level: 
Learning Goals: 
Students will review kinetic rate laws, integrated rate equations, and preparing solution mixtures of known concentrations (from Introductory Chemistry); Students will analyze experimental kinetics data: fitting first-order and second-order rate laws and determining an experimental rate law; Students will evaluate how an experimentally-derived rate law can be used to support or reject proposed mechanisms.
Equipment needs: 
UV-vis spectrophotometer (experiment provides directions for using common Agilent/HP instrument); 100-1000 microliter autopipetters;
Implementation Notes: 
See INSTRUCTOR NOTES for full list of reagents and equipment, some notes and sample results.
Time Required: 
two 3-hour lab sessions

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